In her testimony on the economic outlook and monetary policy, Yellen said that some recent economic indicators have pointed to weaker consumer spending than had been expected, but the central bank needs more time to judge how much the weather has played a role.

She also reaffirmed that it's appropriate for the U.S. central bank to keep accommodative monetary policy in place for some time.

The U.S. central bank's stimulus tapering would likely boost the greenback, making dollar-priced oil more expensive for countries using other currencies, dampening the demand for oil.

On the economic front, the number of Americans who initially applied for jobless benefits in the week ending Feb. 22 rose 14, 000 to 348,000, the Labor Department said Thursday, which exceeded market expectations.

Meanwhile, new orders for manufactured durable goods in January decreased 2.2 billion U.S. dollars, or 1 percent, to 225 billion dollars, reported the Commerce Department. The decrease came less than analysts' forecast.

Light, sweet crude for April delivery moved down 19 cents to settle at 102.4 U.S. dollars a barrel on the New York Mercantile Exchange, while Brent crude for April delivery lost 56 cent to close at 108.96 dollars a barrel.